Kläsges, R. (Corresponding author) ; Institut für Festkörperforschung (Jülich) ; Universität (Köln)

1995
Forschungszentrum Jülich

Report No.: Juel-3041

Abstract: The electronic structure of thin epitaxial Cu films on Co(lOO) has been studied by spin- and angle-resolved photoemission. Due to the quantization of bulk bands in a layer structure discrete states of sp symmetry are observed in the Cu overlayer, which are described in the framework of quantum well (QW) states. QW states in Cu on Co(lOO) are found to be spin-polarized up to Cu film thicknesses of more than 20 atomic layers. They are predominantly of minority spin with a weak exchange split majority spin feature. The experimental results agree well with an ab initio calculation of QW states in Cu on Co(lOO). Spin-polarized QW states can be explained in terms of spin-dependent partial reflections at the Co/Cu interface, leading to a different degree of confinement of majority and minority spin states in the overlayer. This description accounts also for the long-range indirect coupling between ferromagnetic layers separated by a Cu(lOO) spacer and thus provides a common basis on which both spin-polarized QW states and oscillatory magnetic coupling can be understood.

Keyword(s): photoemission ; quantum well ; copper ; cobalt

1. Institut für Festkörperforschung (IFF)